Hitherto, power modules constituted by mounting semiconductor elements such as insulated gate bipolar transistors (IGBTs) and diodes, resistors, and electronic components such as capacitors on a circuit board have been known.
These power modules are applied to a variety of instruments depending on the voltage resistance or current capacity thereof. Particularly, from the viewpoint of the recent environmental issues and energy-saving initiative, the use of these power modules in a variety of electric machines has been expanding every year.
Particularly, for in-vehicle power control devices, there is a demand for the installation of power control devices in engine rooms in addition to size reduction and space saving. In engine rooms, the temperature is high and severe environments such as significantly changing temperatures are formed, and thus substrates having a large heat dissipation area are required. In such applications, metal-based circuit boards having more favorable heat dissipation properties are gaining attention.
For example, Patent Document 1 discloses a power module in which a semiconductor element is mounted on a support such as a lead frame, and the support and a heat dissipation plate that is connected to a heat sink are adhered to each other through an insulating resin layer.